/Engine/Source/Runtime/MeshDescription/Public/MeshDescription.h
Return the internal edges of this polygon, i.e. those which separate constituent triangles
template<typename Alloc> [TArray](API\Runtime\Core\Containers\TArray)< [FEdgeID](API\Runtime\MeshDescription\FEdgeID), Alloc > GetPolygonInternalEdges ( const [FPolygonID](API\Runtime\MeshDescription\FPolygonID) PolygonID ) const